The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
An internal combustion engine combusts an air and fuel mixture within cylinders to drive pistons, which produces drive torque. Air flow into the engine may be regulated via a throttle. More specifically, the throttle adjusts throttle area, which increases or decreases air flow into the engine. As the throttle area increases, the air flow into the engine increases. A fuel control system adjusts the rate that fuel is injected to provide a target air/fuel mixture to the cylinders and/or to achieve a target torque output. Increasing the amount of air and fuel provided to the cylinders increases the torque output of the engine.
Some transmission control systems control a plurality of solenoids to shift gears of an automatic transmission. In one example, the transmission control system actuates (e.g., opens) one or more solenoids to shift the transmission to a particular gear. The transmission control system actuates a solenoid by adjusting the pressure in a line that supplies hydraulic fluid to the solenoid. In another example, the transmission control system increases the hydraulic pressure supplied to a solenoid to actuate the solenoid.
Manual transmissions require a driver to actuate a clutch pedal and select a gear ratio using a gear selection lever. The number of gear ratios available to the driver to select in a manual transmission may be five to 7 although a greater or lesser number of gear ratios may be possible. A continuously variable transmission is an automatic transmission that can adjust its gear ratio continuously to a large number of gear ratios between maximum and minimum values.